Automatic firing mechanism



March 27, 1962 T. R. wooDERsoN In 3,026,777

AUTOMATIC FIRING MECHANISM 5 Sheets-Sheet 1 Filed May 2, 1958 March 27, 1952 T. R. wooDERsoN m 3,026,777

AUTOMATIC FIRING MECHANISM 5 Sheets-Sheet 2 Filed May 2, 1958 March 27, 1962 T. R. wooDERsoN m 3,025,777

AUTOMATIC FIRING MECHANISM Filed May 2, 1958 3 Sheets-Sheet 3 will:

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IN VEN TOR.

THOMAS R. wooesO/v ZZZ.'

BY @dn a fww 3,Zh,777 Patented Mar. 27, 'i962 3,026,777 AUTGMATIC FMNG MECHANISM Thomas R. Woodcrson Ill, 609 S. Campbell Road, Royal Oak, Mich. Filed May 2, 1958, Ser. No. 733,249 9 Claims. (Cl. 89-149) This invention relates to firearms and particularly to those of the submachine gun type. This application is a continuation-in-part of US. application Serial No, 305,484 tiled August 20, '1952, and now abandoned.

In the training of personnel for municipal police work o1' for the armed forces, training involving the use of and practice with a submachine gun is frequently very desirable; but a major drawback encountered which often narrowly limits such training is the high cost of ammunition used in the standard calibre submachine gun. This has been only partially remedied by providing small calibre submachine guns of the same size and weight as the standard guns. Such small calibre guns are as expensive or more expensive than the standard calibre. The cost of duplication of the guns, or the high cost of arnmunition for the standard calibre guns, has in some instances precluded altogether training with the submachine gun in small municipal police forces. Therefore, if one gun s provided which may tire both the standard calibre ammunition and small calibre ammunition, a great saving in expense would result, rendering feasible training of personnel ywith such guns.

An object of this invention is to provide a gun of the submachine gun type that is adapted to tire both the standard size ammunition used in such guns, or a small calibre ammunition such as that of .22 calibre.

Another object is to provide a subrnachine gun capable of tiring various calibre ammunition being adapted for such use by having interchangeable barrels, bolts, and magazines.

A meritorious feature of this invention is the provision in an interchangeable calibre submachine gun of a receiver adapted to receive interchangeable bolts each capable of properly tiring and ejecting a different size ammunition.

A further meritorious feature is the provision, in a gun ceiver having a buffer member adapted to absorb the shock of the tiring of various size calibre ammunition.

A further meritorius feature is the provision, in a gun of the type described, of a tire-control selector which limits the movement of the trigger, thereby selecting in the alternative either the safety, the semi-automatic, or full automatic operation.

Another object of the invention is the provision in a machine gun of a bolt carrying a spring-loaded hammer adapted to be cocked by a cooking scar on the receiver as the bolt travels forwardly in the receiver, with a tiring scar for holding the hammer cocked upon release thereof by the cooking sear, and with cocking sear release means to release the cooking sear from engagement with the hammer following forward movement of the bolt to a point at which the tiring sear may engage and hold the hammer cocked during further movement of the bolt.

Other objects, advantages, and meritorious features will more fully appear in the following claims, specifications, and drawings, wherein:

FIG. 1 is a side elevation in cross section of the invention;

FlG. 2 is an exploded partially sectioned view of the invention shown in FIG. l;

FlG. 3 is a cross sectional view taken on line 3-3 of FIG. 2;

FIG. 4 is a cross sectional view taken on line 4 4- of FIG. 2;

FIG. 5 is a partial side elevation of the invention embodying the receiver and cooperating parts;

FIG. 6 is the same as FlG. 5 but showing the bolt in a different operative position;

FIG. 7 is a detail view through a part of the bolt and receiver' showing particularly the cocking mechanism;

FIG. 8 is a cross sectional view taken on line 8 8 of FIG. 5;

FIG. 9 is a cross sectional view taken on line 9-9 of FIG. l;

FIG. l() is a detail sectional view through the tiring pin and hammer when the gun is in the cocked position;

FIG. l1 is a detail sectional view through the tiring pin and hammer when the gun is in the uncocked position;

FIG. 12` is a schematic view of the bolt illustrating the movement and operation of the ejector;

FIG. 13 is a fragmentary cross sectional view taken along the same plane as FIG. 5 but showing a modified form of the combination ring pin and hammer means and a modified form of the cooking scar, with the parts in the cocked position; and

FIG. 14 is similar to FIG. 13 but shows the relationship of the parts at the instant of firing the gun.

The Barrel alla' Receiver Assembly The invention contemplates a recoil operated gun having a receiver 10, a barrel 12, a magazine 14, and a pistol grip stock i6. The receiver, shown in detail in FIG. 2, is a hollow tube-like member, open at both ends and eX- ternally threadedvadjacent thereto. A cap 1S, internally threaded, is adapted to be threadedly received over the rear end 2G of the receiver thereby closing that end. An internally threaded collar 22 is adapted to be threadedly received over the forward end 24 of the receiver. The collar is also adapted to encircle the barrel 12 and bear against the circumferential shoulder 26 thereon, thereby securing the barrel to the receiver. An extension 2S of the barrel is adapted to be slidably received within the passage 29 of the receiver at the front end thereof.

A longitudinal slot 36 is cut in the outer Wall of the extension 28 of the barrel and is adapted to register with a shoulder 32 raised in the passage 29 of the forward end of the receiver 10, Such shoulder and slot when intertting thereby prevent rotation of the barrel within the receiver. Upon insertion of the barrel within the front end of the receiver and the tightening of the collar 22, the shoulder 26 of the barrel is drawn up against the end of the receiver, as shown in FIG. l.

The bore 34 of the barrel is enlarged in that portion thereof lying within the extension 28, so that a cartridge 36 may be slidably received therein. A barrel grip 38 and a front sight 40 are adapted to be secured to the barrel as shown in FIG. 1.

Bujer Assembly A buler member 42 having at the rear end a circumerential shoulder 44 is adapted to be slidably received within the bore 45 of the receiver 10, with its forward movement therein limited by said shoulder in abutting the rear end face of the receiver. A spring 44, adapted to be received in a recess 46 of the buifer, urges the buffer forwardly in the receiver when the cap 1S is threaded over the rear end 2t) of the receiver.

Two longitudinal recesses 48 and 50 are formed in the lforward end of the butler 42 and adapted to receive and seat a pair of springs 52 and 54. A longitudinal passage 56 aligned with the recess 48 and opening thereinto, opens rearwardly through the face 58 of the butter.

3 Bolt Assembly A bolt member 60 is adapted to be slidably received,

in the bore 45 of the receiver 10. The bolt is provided with a pair of recesses 62 andv 64 complementing the recesses 43 and 50 in the buifer and adapted to receive and seat the opposite ends of springs 52 and 54. A longitudinal passage 66 aligned with and opening into recess 62 extends into the body of the bolt. Another longitudinal passage 68 aligned with and opening into recess 64 extends through the body of the bolt and opens through the forward face 70 thereof. A pair of guide rods '72 and 74, encircled respectively by springs 52 and 54, are adapted to be slidably received within passages 56, 60, and 68 of the bolt and buffer, serving thereby to maintain the bolt and buffer in constant reflected positions, and to prevent buckling of said springs upon compression thereof. Springs 52 and '54 tend to space apart the buffer and bolt and urge the same in opposite directions within the bore of the receiver.

The bolt 60, shown particularly in FIGS. 2, 3, and 8, is bifurcated throughout the rear portion thereof, providing the arms 76 and 78. A pair of longitudinal concave depressions 80 and 82 are formed diametrically opposed on the opposite inside faces of the arms 76 and 78. These depressions are longitudinally flush with the circular bore of passage S4 formed in the forward portion of the bolt, as shown particularly in FIGS. 2 and 3. Passage 84 terminates short of the forward end -face 70 of the bolt. A small longitudinal passage 86a, axially offset, opens into passage 84 and out through the forward end face '70 of the bolt. Y

A pair of opposed outwardly opening channels 36 and 88 are respectively formed in the upper and lower portions of the bolt. Both channels open forwardly through the end face 70, and rearwardly into the slot formed by the bifurcated' rear end portion of the bolt. The upper channel 86 is substantially deeped than the lower channel for a purpose hereinafter disclosed.

E jector Assembly Referring particularly to FIGS. 2 and 8, an outwardly opening linear channel 81 is formed in the upper half of the bolt and extends throughout the length thereof. Said channel is adapted -to receive ejector 83.l The ejector is provided at its forward end with a lip portion 85 vand at its rear end with a nose portion 87. A recess 89 formed in the rear half of the ejector is adapted to overlie a shoulder (not shown) formed on the bottom wall of the channel 81; said shoulder being of a length substantially less than the length of said recess, so that the ejector may reciprocate linearly within the channel. Formed in each end face of the bolt and adjacent each end of channel S1, isa recess (not shown) which-is adapted to receive the respective end portions 8S and 87 of the ejector. The provision of these recesses permits the respective ends of the ejector to lie flush with the corresponding end faces of the bolt when the ejector is reciprocated within the channel. The operation of the ejector will be described hereinafter.

A longitudinal channel 90 is formed in one side of the bolt, and opens outwardly and forwardly through the end face 70, while rearwardly it terminates within the body of the bolt, particularly as shown'in FIGS. 2 and 4. A lever 92, having a lip 94 adapted to partially overlie the end face 70, is pivotally mounted upon pin 96 within channel 90 of the bolt.

Firing M echansm The operating parts of the bolt, other than the ejector, above mentioned, will now be described, as is best shown in FIG. 2. Aring pin 98 having: an axially offset longitudinal contact finger 100 projecting from its forward end, a longitudinal and axial retracting spring recess 102 opening rthrough the forward end and extending into the'body of the firing pin, and a transverse substantially semi-circular groove 104 formed on a vertical diameter of the rear end face of the tiring pin as shown -in FIG. l0; is adapted to be slidably received within the cylindrical passage S4 of the bolt, with said finger 100 slidably interiitting with longitudinal passage 86a in the forward end of the bolt. The length of nger 100 is such that when a cartridge is backed up by the bolt, as shown in FIGS. 1 or 5, and the ring pin is urged forwardly, the finger will contact said cartridge before the ring pin has moved as far forwardly as is permitted by the termination of passage 84 in which it slides. A retractor spring 106 seated within recess 102 and bearing against the forward end of passage 84, reacts with the firing pin to urge said pin rearwardly within the bolt.

Limiting this rearward urging of the tiring pin by spring 106, is a stop pin 108 disposed transversely within the bolt and extending across passage 84. In limiting the rearward movement of the tiring pin, the stop 1018 is partially encircled by the rear end of the firing pin by virtue of the groove 104 formed in said end as shown in FIGS. 10 and ll. Groove 104 is of a sufficient depth to permit the rear face of the firing pin to completely by-pass the stop and thereby extend rearwardly beyond said stop, all as shown by the dotted outline in FIG. 10.

A firing pin hammer 110, adapted to be slidably received within passage 84 and rearwardly of the firing pin, is provided with the following: a longitudinal passage 112 extending into the body of the hammer and opening out through the rear face thereof; a circumferential shoulder 114 adjacent to and ush with said rear face of the hammer, with the lower portion of said shoulder beveled las shown in the drawings; and a forward end face complementing the rear end face of the ring pin, viz., provided with a transverse substantially semi-circular groove 116 adapted to permit partial encirclement of stop 108 by said hammer when the latter is in itsextreme forward position within the bolt as shown in FIG. 6 and suggested in FIG. 10. The firing pin 948 and hammer y110 may be considered together as ring pin means.

A spring 118 encircles a spring guide 120 and both are adapted to be slidably received within the passage 112 of the hammer to permit reciprocation of said Vhammer thereover. The guide 120 is provided with a circumferential shoulder 122 against which the rear end of spring 118 abuts, and a reduced diameter exterior beyond said shoulder which interts with a cooking cam 124. The cam carries and positions the guide 120 centrally of passage 112 in the hammer. Cam 124 shaped as shown in the figures is rigidly mounted within the bifurcation and at the rear end of the bolt. It is provided with cock- -ing sear release means in the form of a beveled cam face 126 at its top forward edge, and a central upwardly exing recess 128 adapted to receive a spring 130.

Trigger Mechanism A tiring sear 132, pivotally mounted on pin 134, is carried by the bolt 60 at the lbottom and within the bifurcated rear end portion thereof. The sear 132 is provided with a tapering forward end 136 which is adapted to lie within the channel 88 along the bottom of the Ibolt. The taper of end 136 of the sear is suicient to permit a rocking motion of said sear when the bolt is resting within the bore of the receiver. The sear 132 is further provided with a shoulder 138 having a forward beveled face and a rear face adapted to engage shoulder 114 on the hammer, and hold the hammer against the reaction of spring 118. The scar is normally held in a position such that shoulder' 138 on the sear and shoulder 114 on the hammer are in the above mentioned engagement, by the reaction of spring 130. A guide 140 mounted on the scar, is slidably received within spring 130, and adapted to reciprocate within recess 123 of the cam when the sear is rocked about its pivot. Y

Adapted to rock the sear is a -sear cam 142 pivotally mounted within an opening 144 in the bottom of the receiver. This sear cam is shaped to define three cam faces 146, 148, and 150. A trigger 152 is pivotally mounted within the opening 144 of the receiver. A spring loaded plunger 154 is received within passage 156 in the upper end of the trigger, and is permitted limited reciprocal movement therein by any desirable means.

The pistol grip 16 is shaped to define an open frame portion 158 and a solid portion 160, cut away at its forward end to provide an opening and a linger guard 162. Provided within solid poition 160 of the pistol grip is a passage housing a reciprocable spring loaded plunger 164 which is adapted to bear against and urge forwardly the trigger. Forward movement of the trigger is limited by a shoulder 166 formed on the upper forward corner thereof which is adapted to abut an upper portion of the finger guard 162.

Asy Vshown in FIGS. 2 and 9, a bifurcated trigger stop 168 is adapted to be slidably received over the forward edge of portion 160 of the pistol grip. Three small depressions 170, 172, and 174 above one another are formed in the side of portion 160 of the pistol grip. A spring 176 is seated in a recess formed in one arm of the bifurcated trigger stop 168, and provided at one end with a detent 178 adapted to be received in any of said small depressions. The trigger stop is adapted to slidably move upon portion 160 of the pistol grip so that the detent 178 will rest in said depressions at three selected positions of said slidable movement. When the detent rests in a depression, the trigger stop is yieldingly held in the respective selected position.

Cooking M echan ism Offset in the top of the receiver 10, in a linear opening 180 through which is adapted to extend a bolt handle 182 mounted on the bolt, and adapted to be used for manually cooking the ring mechanism in a manner hereinafter described.

Another opening 184 is formed in the top of the receiver. A cocking cam follower or cooking sear 186 is adapted to be received `within opening 184, and to be yieldingly supported therein by fiat springs 18S, themselves mounted within said openin g in a manner apparent from the drawings. The opening 184 is closed at the top by a plate 19th yand is held by fasteners to the receiver. The cooking sear 186, shaped as shown, is provided with a lip portion 192, and a beveled face 194. Because the cocking sear is supported within the opening 184 by springs 188, a limited amount of movement may be imparted to it. 1t is adapted to rest normally with lip 192 extending downwardly into the receiver a distance sufficient to engage the shoulder 114 on hammer 110, `and hold the hammer from forward movement, as shown in FIG. 7. The purpose and operation of these parts will be hereinafter described.

Magazine as 14 in the drawings enters the lower wall of the receiver through an opening 196 therein. As shown in FIG. 7 the magazine is held in place by a spring element 198, mounted on the magazine `at one end, and provided at the other end with a detent 200 adapted to interiit with a recess in the receiver 10.

Operation In the operation of the gun the magazine is first loaded with cartridges of a size adapted to be fired by the particular size barrel and bolt assembly that are mounted on `the receiver. After the magazine is loaded it is fitted into the receiver being held therein as heretofore described. A pair of lips on the upper end of the magazine together with the bolt `as shown in the position of FIG. 5 serve to prevent the cartridges from being prematurely ejected from the magazine upon its insertion within the receiver. The gun is now cocked by manually drawing rearwardly the bolt handle 182 which in turn draws the bolt with it. During the rearward movement of the bolt the springs 52 and 54 are compressed and upon release of the bolt handle they drive the bolt forwardly.

During the forward movement of the bolt from its extreme rearward position shown in FIG. 6, the bolt slides beneath the cooking sear 136. When it reaches the position shown in FIG. 7 the lip 192 on said sear engagesthe shoulder 114 ou the hammer 110 Vand there by prevents continued forward movement of the hammer while the bolt continues to slide forwardly. During the continued forward movement of the bolt, the lower forward edge thereof picks up the topmost cartridge in the magazine and carries it forward into the breech. With the continued forward movement of the bolt and the retention of the hammer as described, the spring 118 within the recess 112 of the hammer is compressed. As the bolt nears the forward limit of travel the beveled face 126 of the cooking cam 124 abuts the complementary beveled face 194 of the cocking sear. At substantially the same instant that those two beveled faces abut one another the shoulder 138 on the firing sear 132 rides under the complementary lower por-tion of shoulder 114 on the hammer until by the action of spring 130 the firing sear is positioned to engage the lower portion of shoulder 114 on the hammer. Continued forward movement of the bolt at this instant forces the cooking cam to raise the follower or cooking sear 186 and release the hammer, but any forward movement of the latter is arrested by shoulder 114 on the hammer engaging the shoulder 138 on the firing sear 132. The hammer is now held in the cocked position and the bolt has moved to its extreme forward position as shown in FIG. 5.

The `bolt in the extreme forward position shown in tFIG. 5 backs up the cartridge in the breech that it previously had picked up. The firing pin 98 rests normally seated against the stop 168 held thereagainst by spring 106. It should also be noted that the lip S5 on the ejector is seated behind the cartridge while the lip 94 of `the lever 92 overlies the rim of the cartridge as shown in FIG. l2.

The gun is now ready kto be fired. It may be tired either continuously in the Automatic or selectively in the Semi-automatic settings of the selector 16S. From the safety position shown in FIG. l the selector may be moved downwardly to the Automatic position wherein the detent 178 in the selector registers with the middle depression of the three depressions in the pistol grip. With the selector in the Automatic position the trigger may be pivoted rearwardly until it abuts the selector. During such movement of the trigger the spring loader plunger 154 in the trigger rocks the firing cam 142 such that face 148 of the cam raises the rear end of the sear releasing 4the hammer. As the hammer begins its forward movement the tiring pin is seated against the stop y108 as shown in FIG. l0. The hammer strikes the pin driving it forward against the cartridge while at the same instant the hammer comes to rest against the stop 163. FIG. ll illustrates the relative position of the hammer, pin, and stop after the pin has returned from striking the cartridge and before the hammer has been recocked.

Upon explosion of the cartridge the bolt and expended shell casing are driven rearwardly against the reaction of springs 52 and S4 until the bolt abuts the buffer 42. Upon impact with the buffer `the nose portion 87 on the ejector strikes the buffer driving the ejector forward and tipping the expended shell casing out through port 202 in the side of the receiver. The bolt then begins its forward movement the description of which Ais identical withrthe foregoing description thereof with the exception of the following.

When the selector is in the Automatic position and the trigger is held back against the selector the firing sear is not permitted to engage the shoulder 11,4 of the hammer and stationarily retain the hammer after release thereof by the cooking sear 186. Rather, upon release of the,

hammer by the lcooking Sear, the hammer immediately is allowed to drive forwardly against the tiring pin to fire the next cartridge. This oper-ation is continuous until all the cartridges in the magazine are expended or until the trigger is released. y v l v The selector maybe moved to the Semi-automatic positionV wherein the detent 17S registers with the lower depression in the pistol grip. In this position :a greater amount of swing is allowed the trigger so that upon the rearward movement thereof face 150 of the firing cam raises the firing sear to release the hammer; The increased permissive swing of the trigger is suf'licient to allow spring loaded plunger 154 in the trigger body to bypass lip 151 of the firing cam. The firing cam is thereupon-disengaged from the trigger and upon the forward movement of the bolt, after the cartridge has been fired, v

Inl the safety position of the selector the trigger cannotl be pivoted and therefore the firing sear `cannot be raised to release the hammer.

A slight modification of the combination pin andV hammer means is shown in FIGS. 13 and 14,` as `wellas a modification of the cooking soar. In these figures ythe firing pin and hammer are one integral element, the Vhammer carrying the firing pin. The hammer 204 is generally similar to the hammer heretofore shown and describ,edV

but differs therefrom in that it is somewhat longer and has an integral firing pin 206 adapted to project through aperture 208 in the front wall of bolt 60. A slot 211i milled along the top of the bolt, allows the cooking sear 212, pivoted at 214 on the receiver, to extend below the upper surface of the bolt during reoiprooation of the, bolt.

The `cooking sear 212 is spring-tensioned as at 216 to-u ward a position for engagement with the shoulder 114 of the hammer to cock the hammer during forward travel of the bolt. The cooking sear has a shoulder 218 which enigages shoulder 114 of the hammer for cooking purposes. The sear also has a cam surface 220 which the cooking sear release means 124 engages to effect disengagement of the sear from the hammer. The cooking sear also has a surface 22 for limiting the down swing.

The operation of the-elements shown in FIGS. 13 and 14 is esentially the same as the operation heretofore described in connection with the other figures. The cooking sear pivots at 214 rather than moving as shown in FIG. 5. The hammer 204 with its integral firing pin eliminates the pin 108 and separate firing pin 198 heretofore described, but functions to re a cartridge in the chamber of the gun in an obvious manner.

What I claim is: l

1. In a firearm of the recoil operated type, ya receiver, a bolt slidably disposed in the receiver, means disposed in the receiver rearwardly of the bolt and adapted to urge the bolt forwardly in the receiver, a firing pin slidably disposed in the forward end of the bolt, means yieldingly spacing saidkpin from the forward end face of the bolt, a firing pin hammer slidably disposed in the bolt behind said pin, spring means yieldingly spacing said hammer from the rear end of the bolt, a cooking sear yieldingly mounted on said receiver to engage said hammer ywhen.V thebolt moves' forwardly through/the receiver, a `firing,A sear mounted on the bolt to engage said hammer asfth'e` bolt moves forwardly through the receiver, cam means A mounted on the rear end of said bolt to engage the cocking sear to move said sear to a position of disengagement withsaid hammer as the bolt moves forward through the receiver, and spring means` mounted on said cam means and engaging the firing sear to urge said sear into looking engagement with the hammer upon release of said hammer by the cooking seat. Y

2.l In a firearm, a receiver shaped to define a generally ,cylindrical bore closed at the rear end, a bolt slidably i end of the bolt, a cooking sear mounted on the receiver with a part engageable with the hammer toV hold the hammer stationary during forward movement of the bolt, oaming. means mounted on Vthe bolt to engage the cooking Sear after a determined forward movement ofthe bolt to urge said part into a position of disengagement with the hammer, a firingy sear mounted on the bolt and having `a part tensioned toward the hammer to engagey and hold the hammer cocked following release thereof by saidV cooking sear,V and firing `sear actuating means mounted on the receiver to` engage the firing seary and shift the same to disengage the firing sear from the hammer.

Y 3. In a firearm, .a receiver shaped Yto define a generally cylindrical boreclosed at the rear end, a bolt slidably disposed in the bore, means disposed between the bolt and the rear end of the bore to urge the bolt forwardly in the receiver, a hammer slidably disposed in the bolt,l

means tensioning .the hammer toward the forward end of the bolt, a cooking sear mounted onthe receiver and having .a part yieldingly tensioned toward the path of movement of the hammer as the bolt moves in the receiver and engageable with the hammer to hold the same stationary during forward movement of the bolt, a cocking sear follower mounted on the bolt with a portion shaped to define a camming shoulder, said Sear having a portion shaped to define a camming surface complementing the camming shoulder of the follower and disposed in the path of movement of the follower as the bolt moves forwardly in the receiver, said camming surface and shoulder abutting each other after the bolt has reached a determined point of forward movement in the receiver and urge the cooking sear away from the hammer and out of engagement therewith, and a firing searv mounted -on the bolt and tensioned toward the hammer and having a part engageable with the hammer to hold the latter cooked following release of the hammer by the cooking sear.

4. In a firearm, areceiver shaped to define a generally cylindrical bore closed at the rear end, a bolt slidably disposed in the bore, means disposed between the bolt and the rear end of the bore to urge the boltforwardly in the receiver, a firing pin .slidably mounted in the forward end of the bolt, a firing pin hammer slidably disposed in the bolt and provided with a sear engaging shoulder, means disposed within the bolt tensioning the hammer toward the firing pin, a cooking sear mounted on the receiver with a part engageable with the hammer to hold the hammer stationary during forward movement of the bolt, camming means mounted on the bolt to engage the cooking sear after a determined forward movement of the` bolt to urge said part into a position of disengagement with the hammer, a firing sear mounted on the bolt for movement therewith and provided with a hammer engaging shoulder to engage said sear engaging shoulder of the hammer and hold the hammer against forward movement in the bolt, said hammer engaging shoulder of the scar being normally disposed rearwardly of the sear engaging shoulder of the hammer and movable forwardly with the forward movement of the bolt to a position disposed ahead and in the path of travel of the sear engaging shoulder of the hammer when the hammer is held stationary by the cooking sear and before the camming means disengages the cooking sear from the hammer.

5. In a recoil operated type of firearm: a receiver, a bolt slidably received in the receiver, spring means yieldingly urging the bolt toward the front end of the receiver, a firing pin slidably received in the front end of the bolt, a firing pin hammer slidably received in the bolt behind the tiring pin, spring means yieldingly urging said hammer toward the firing pin, a cooking sear cooperable with the receiver and with the hammer to cock the hammer during forward movement of the bolt, a firing sear mounted on the bolt to engage the hammer and hold it cocked, and cooking sear release means cooperable with the bolt and with the cooking sear to release the cocking Sear from engagement with the hammer following forward movement of the bolt to a point at which the tiring sear may engage and hold the hammer cocked during further movement of the bolt.

6. In a rearm of the recoil operated type, a receiver, a bolt slidably disposed in the receiver, spring means yieldingly urging said bolt toward the forward end of the receiver, a iiring pin slidably disposed in the front end of the bolt, a liring pin hammer slidably disposed in the bolt behind said firing pin spring means yieldingly urging said hammer toward the front end of the bolt, a cooking sear mounted on said receiver to engage said hammer during a forward movement of the bolt, a tiring sear mounted on the bolt to engage said hammer, means mounted on the bolt to disengage said cooking sear from said hammer at a determined point of forward movement of said bolt and urge said firing sear into locking engagement with said hammer.

7. In a firearm, a receiver, a bolt assembly slidably received in the receiver, liring pin means slidably received in the bolt assembly, spring means yieldingly urging said firing pin means forwardly in the bolt assembly, a tiring sear mounted on the bolt assembly to engage and hold said firing pin means in opposition to said spring means, a firing sear cam rotatably mounted on the receiver, said cam provided with three faces with two of the faces operable to shift the sear to a position of disengagement with the firing pin means and the third face inoperative to engage the sear, a trigger mounted on the receiver, means adjustably limiting movement of the trigger, and spring-loaded connecting means extending between the trigger and sear cam and operable when the trigger is moved to one position to rotate the scar cam to present one of said two faces to the sear to shift the same and operable when the trigger is moved to a second position to rotate the cam to present the other of said two faces to the scar to shift the sear and disengage itl self from the cam to permit free rotation of the cam to present the third face to the sear.

8. The invention as defined in claim 7 characterized in that said spring-loaded connecting means is a springloaded finger movable with the trigger, and said sear cam is provided with a lip engaged by said linger with the iinger bearing against the lip to rotate the cam during movement of the trigger, and said linger and lip are disengaged when the trigger is moved to the second position whereby the said cam may freely rotate to a position disposing the third cam face opposite the sear and the spring-loaded finger may re-engage said lip when the trigger is moved to a third position.

9. In a firearm of the recoil operated type: a receiver, a bolt slidably disposed in the receiver, first means yieldingly urging the bolt toward the front end of the receiver, firing pin means slidably disposed in the front end of the bolt, second means yieldingly urging said tiring pin means toward the front end of the bolt, a cooking Sear cooperable with the receiver and with said firing pin means to engage and cock the latter against the tension of said second means during movement of the bolt toward the front end of the receiver, a pivoted tiring sear oooperable with said bolt and said firing pin means and having a holding shoulder forward of the pivot to engage and hold the tiring pin means latter cocked against tension of said second means when the bolt is at the extreme front end of the receiver, cooking sear release means cooperable with the bolt and with the cooking scar to release the cooking scar from engagement with said tiring pin means following movement of the bolt toward the front end of the receiver to a point at which the liring sear may engage and hold said firing pin means cocked during further movement of the bolt, and a firing sear actuator mounted on the receiver and having a camming surface shiftable into and out of the path of the firing sear during forward movement of the bolt and shiftable to a position engaging the firing sear and camming it to a position out of the path of slidable movement of the firing pin means prior to release of the firing pin means by the cooking sear during forward movement of the bolt.

References Cited in the tile of this patent UNITED STATES PATENTS 1,144,994 Berthier July 6, 1915 1,472,126 Kewish Oct. 30, 1923 1,656,961 Soncini Jan. 24, 1928 2,361,519 Williams Oct. 31, 1944 2,366,823 Williams Jan. 9, 1945 2,427,304 Robbins Sept. 9, 1947 2,641,163 Lippert et a1. June 9, 1953 2,831,404 Sampson et al Apr. 22, 1958 FOREIGN PATENTS 391,087 Great Britain July 11, 1931 

